Olefin-polysulphide plastic



Patented Mar. 13, 1934 UNITED STATES OLEFIN-POLYSULPHIDE PLASTIC Joseph6. Patrick, Kansas City, Mo.

assuw N, Drawing. Applicatio'n-Septcmberli), 1929,

Serial No. 393,830

20 Claims. (01. 2so- -e) The present invention relates to improvementsin olefin-polysulphide plastics and more particularly in the type ofplastic described in my prior application 239,808, filed December 13,1927..

In accordance with the present invention, I am able to secure theplastic product of reaction and particularlythe soft-type productscorresponding to polysulphides of the formula IRS:

to R815 and higher proportions of sulphur, in

a form such that the product may be readily and rapidly washed free frominorganic salts and other undesired constituents, and an improvedproduct is secured.

Furthermore, by operating in accordance with olefin-polysulphideplastic, and particularly the soft-type plastic above referred to, inthe form of an aqueous dispersion or latex, which can be readilypurified, and from which the plastic material may be coagulated, eitherwith or without the previous incorporation into the latex of desiredcompounding or stabilizing constituents. In

addition, by securing the plastic material in a. dispersed condition asa latex, I am enabled to coat or impregnate fabrics, textiles andvarious absorbent and non-absorbent bodies with the latex andsubsequently cause the coagulation in situ of the desired plasticbodies.

In carrying out the present invention, I cause the plastic or reactionbody to be formed'in the presence of asuitable dispersing agent, whilemaintaining a hydroxyl ion concentration equal to or greater than thatexisting in a saturated solution of freshly precipitatedmagnesiumhydroxide. As suitable dispersing agents, I may employ precipitatedmagnesium hydroxide, or aqueous dispersions of peptized starch, gelatin,glue, blood-albumen, egg-albumen, or the like. In general I prefer toemploy freshly precipitated magnesium hydroxide in carrying out thereaction.

As pointed out in my prior application above referred to, the plasticmaterial may be produced by reaction between an olefin-dihalide and awater-soluble polysulphide having the desired sulphur content, thereaction being quantitative. Ordinarily an excess of one of the reactionconstituents is desired, and since the polysulphide is the leastexpensive reagent, it is preferred that there be an excess of thepolysulphide present. The polysulphide employed may be previouslystabilized by heating for a period such that homogeneity is secured, asset forth in my prior application 369,912, filed June 10. 1929, and theconditions of reaction, particularly as to temperature, may becontrolled by the addition of alcohols as disclosed in said application.Thus, when used, the proportion of alcohol may vary from 10 to 80% byvolume. Where such control is not desired, the alcohol may be omitted.

the present invention, I am able to secure the' The invention may beillustrated by the following examples:

I. An aqueous solution of calcium polysulphide is prepared, having adensity of 31 B., the em pirical formula of which is, by analysis, CaSn.Magnesium hydroxide is formed in this solution, preferably by theaddition of a solution of sodium hydroxide, followed by a solution ofmagnesium chloride or sulphate, or other suitable compound. The amountof magnesium hydroxide may vary within quite wide limits say from 2 to50 grams per thousand cubic centimeters of the polysulphide solution.Preferably from 5 to 10 grams per liter provides a desirable form oflatex-like dispersion of the final product best adapted for handling.Thus, to each 1000 cubic centimeters of the above calcium polysulphidesolution, there may be'added 50 cubic centimeters of a solutioncontaining 290 grams sodium hydroxide per liter and 100 cubiccentimeters of a solution of magnesium chloride containing the chemicalequivalent of 105 grams of magnesium hydroxide per liter, theseproportions providing a slight excess of sodium hydroxide. Asemi-gelatinous dispersion of magnesium hydroxide in the polysulphidesolution results. If desired, the magnesium hydroxide suspension may beformed'separately and added to the polysulphide solution, but preferablythe suspension is formed in the solution itself, as hereinbeforedescribed.

* The desired olefin-dihalide, for example, ethylene dichloride, is nowadded to the polysulphide solution containing the dispersed magnesiumhydroxide, the proportion of dihalide added being very slightly lessthan the equivalent required for reaction. Thus, with the solution abovedescribed, 157 cubic centimeters of ethylene dichloride per liter oforiginal calcium polysulphide solution is used. To avoid excessiveheating, the olefin-dihalide is added in small portions with vigorousagitation. If desired, the polysulphide solution may first be slightlywarmed, say to 80 to F., to accelerate the beginning of the reaction.The addition of ethylene dichloride is controlled so that thetemperature does not rise excessively, say to above 150 to 175 F. Afterthe dihalide has been completely'added, the reaction may be completed byfurther warming the mixture to, say, 175 to 190 F. for a short period,until complete disappearance of the olefin-dihalide is indicated by lossof its odor. The olefin-polysulphide plastic forms in this reactionmixture as a fluid dispersion, latex-like in character, which settlesout of the reaction mixture.- The supernatant solution may be removed bydecantation and the latex-like dispersion may be readily washed withwater and settled, the wash water being decanted. This is repeated untilthe soluble salts and other undesirable constituents present arecompletely removed. This latex may then be coagulated or compounded andcoagulated, as hereinafter set forth.

II. A stabilized sodium polysulphide solution of empirical formulaNazsl, and of density 37.0 B. at F. is formed by dissolving sulphur in asolution of sodium hydroxide in the requisite proportions and heatingthe mixture to atmospheric pressure boiling point for a substantialperiod of time, say 20 hours, as disclosed in my prior applicationSerial No. 369,912, above referred to. Dispersed magnesium hydroxide isformed in this polysulphide solution in the same manner and suitably inthe same proportions as set forth in connection with the first exampleabove. The mixture is then heated to 120 F., and slightly less thanequivalent quantity of ethylene dichloride is added in small portions ata time with vigorous agitation, while'holding the temperature of themixture below about 175 F. The amount of ethylene dichloride so added isabout 208 grams per liter of the original polysulphide solution. Thelatex of olefin-polysulphide plastic forms and is settled and separatedfrom the other products of reaction by decantation or centrifuging,thoroughly washed as in the first example and is then ready forcoagulating or compounding and coagulating.

The latex-like dispersion of the olefin-polysulphide plastic produced inaccordance with the method of the present invention may be coagulated byacidifying it with any suitable acid, such as hydrochloric or sulphuricacid, or organic acids such as acetic acid, formic acid, or the like;and on acidulation, the olefin-polysulphide plastic coagulates to forman elastic, spongy mass, from yellow to white or nearly white in color.The coagulum has the characteristics of the soft plastic described in myprior applications above referred to, being pliable and resembling inappearance soft vulcanized rubber. Its characteristics may be improvedby incorporating into it, suitably on arubber mill, any desirableproportion of a metallic oxide such as litharge, zinc oxide, magnesiumoxide or other compounds of the class of sulphur carriers well known inthe rubber industry. Various inert materials, such as those of the typeused in compounding rubber, for example, fibers, wood flour, carbonblack, glue, asbestos, and the like, may be compounded with the latexeither with or Without the sulphur carrier. The compound may then besuitably heated to effect its stabilization, the time of heating varyingwith the temperature employed. Temperatures from C. upwards may be used.Thus, by heating in autoclave under 40 lbs. steam pressure for 40minutes to 1 hour, a completely stable and homogeneous product may besecured. Instead of first coagulating the latex and incorporating asulphur carrier and other compounding ingredients into the coagulum,such materials may be incorporated in the latex before coagulation.Thus, from 1 to 10% of litharge or zinc oxide may be thoroughly mixedwith a thick latex, the mixture then heated (as 'it does not undergocoagulation on heating) under the same conditions as set forth inconnection with the compound above, and the heated and stabilizedmixture: then coagulated. Other compounding ingredients may be in,-corporated in the latex for such heating and coagulation, or if desired,after the stabilized latex-sulphur carrier mixture has been coagulated,additional, compounding ingredients may be milled into the coagulum inthe ordinary manner.

The resulting product has the characteristics of a soft unvulcanizedrubber, does not flow under pressure, is not separable by organicsolvents; it is not affected or swelled by organic rubber solvents,including carbon disulphide, and has dielectric qualities superior tothose of rubber. Furthermore, it completely resists the action of oils,salt water and the like, and has an extremely low power loss when usedas a dielectric.

The latex of the olefin-polysulphide plastic is stable and may bepreserved and stored as such, or may be treated with a sulphur carrier,as hereinbefore set forth, and the stabilized latex preserved and storedfor further use. If the latex is stored forperiods of a week or more, itmay undergo a change somewhat analogous to polymerization. The additionof an acid then produces the subsidence of a granular product from theliquid. The latex can, however, be restored to its original condition bysubjecting the dispersion, before adding the acid, to temperaturesaround the boiling point of water for a few minutes, the addition of theproper amount of acid will then produce the massive coagulum.

The present method of operation is particularly desirable in themanufacture of the softtype of olefin-polysulphide plastic and thoseappreaching the soft-type; that is, corresponding to the polysulphidesof the formula RS3 to RS115 and upwards. It may also be employed in theproduction of olefin-polysulphide plastics of lower sulphur content insecuring dispersed products but as the proportions of sulphur decrease,the resulting product loses its latex-like character and assumes a moregranular, pulverulent character, as in the process described in my priorapplication Serial No. 369,912 hereinbefore referred to.

As pointed out in my prior application, a wide range of olefin-dihalidesmay be employed in carrying out the reaction, as well as dihalides ofmixtures of olefins such as are secured by the formation of unsaturatedhydrocarbon gases derived from pressure cracking processes, natural gascracking processes, and the like. Furthermore, as also disclosed in myprior applications, a wide range of soluble polysulphides may beemployed in securing the reaction products.

I claim:

1. The method of producing an olefin-polysulphide plastic in dispersedform, which comprises reacting upon an olefin-dihalide with a solutionof a water soluble polysulphide in'the" presence of a dispersing agentfrom the group including magnesium hydroxide and dispersions of peptizedstarch, gelatin, glue, blood-albumen, egg-albumen and the like whilemaintaining an alkalinity at least equal to that existing in a saturatedsolution of freshly precipitated magnesium hydroxide.

2. The method of producing an organic poly- 1 sulphide plastic whichcomprises reacting upon an olefin dihalide with a solution of awater-soluble polysulphide in the presence of magnesium hydroxide,thereby forming a latex-like. dispersion of organicpolysulphide bodies.

3. The method of producing an organic polysulphide plastic, whichcomprises reacting upon thereby forming a latex-like dispersion of anorganic polysulphide body.

5. The method of forming a softolefin-polysulphide plastic in latex-likedispersion which comprises reacting upon an olefln-dihalide with anaqueous solution of a polysulphide having a formula RSn, wherein n is atleast 3 and R is the equivalent of two monovalent positive radicals, inthe presence of a dispersing agent from the group including magnesiumhydroxide and dispersions of peptized starch, gelatin, glue, b1ood-'albumen, egg-albumen and the like, while maintaining a hydroxyl ionconcentration at least equal to that existing in freshly precipitatedmagnesium hydroxide.

6. The method of producing a soft olefin-polysulphide plastic inlatex-like dispersion wherein an olefln-dihalide is reacted upon with anaqueous solution of a polysulphide of formula RS wherein n is at least 3and R is the equivalent of two monovalent positive radicals, in thepresence of freshly precipitated magnesium hydroxide.

'1. The method of forming a. soft olefin-polysulphide plastic in theform of a latex-like dispersion which comprises incorporating adispersing agent from the group including magnesium hydroxide anddispersions of peptized starch, gelatin, glue, blood-albumen.egg-albumen and the like into an aqueous solution of a polysulphide offormula RS wherein n is 3 or higher and R is the equivalent of twomonovalent positive radicals, and admixing an oleiin-dihalide with saidsolution.

8. The method of producing a soft olefin-polysulphide plastic inlatex-like dispersion which comprises dispersing magnesium hydroxide inan aqueous solution of a polysulphide of formula RSn wherein n is atleast 3 and R is the equivalent of two monovalent positive radicals;admixing an olefin-dihalide therewith and warming to cause reactiontherebetween, whereby a latex-like dispersion of a softolefin-polysulphide plastic is secured.

9. The method of producing a soft olefin-polysulphide plastic whichcomprises forming dispersed magnesium hydroxide in an aqueous solutionof a polysulphide of formula RS, wherein n is at least 3 and R is theequivalent of two monovalent positive radicals, and adding an ole-;

fin-dihalide thereto, whereby the olefin-polysulphide plastic is formedin latex-like dispersion.

10. The method of producing a soft olefin-polysulphide plastic whichcomprises reacting upon a polysulphide containing a proportion ofsulphur adapted to produce a soft-type plastic, while in aqueoussolution, with an olefln-dihalide in the presence of a dispersing agentfrom the group including magnesium hydroxide and dispersions of peptizedstarch, gelatin, glue, blood-albumen, eggalbumen and the. like forming alatex-like dispersion of the reaction product, removing solubleimpurities from said latex, and coagulating the latex.

11. The method of producing a soft-type 0165 fin-polysulphide plastcwhich comprises incor? porating a suitable dispersing agent from thegroup including magnesium hydroxide and dispersions of peptized starch,gelatin, glue, bloodalbumen, egg-albumen and the like in a solution ofan aqueous polysulphide of the general formula Rsm where'n n is at least3 and R is the equivalent of two monovalent positive radicals, reactingthereupon with an oleiin-dihalide, thereby forming a latex-likedispersion of the olefin polysulphide plasti washing'said latex to rea VI? V like while maintaining an alkalinity at least equal to thatexisting in a saturated solution of freshly precipitated magnesiumhydroxide, thereby forming a latex-like dispersion of anolefin-polysulphide plastic, washing said latex and acidulating thewashed latex, thereby precipitating the olefin polysulphide plastic.

13. The method of forming a soft-type oleiinpolysulphide plastic whichcomprises reacting with an olefin-dihalide upon an aqueous solution of apolysulphide of formula RS, wherein n is at least 3 and R is theequivalent of two monovalent positive radicals, in the presenceof asolution of freshly precipitated magnesium hydroxide, thereby forming alatex-like dispersion of the plastic, separating and washing said latex,and acidulating the latex, thereby coagulating the plastic.

14. A latex-like dispersion of a soft-type olefinpolysulphide' plastic,the type formula of the olefin being CnHan.

16. A latex-like dispersion of an olefin-polysulphide plastic having asulphur content corresponding to a polysulphide of the formula RSwherein n is at least 3 and R is the equivalent of two monovalentpositive radicals.

16. A latex-like dispersion of an organic polysulphide derivativeproduced by the action of an olefin dihalide on a water solublepolysulphide of the formula RSn, wherein n is at least 3 and R is theequivalent of two monovalent positive radicals, said dispersioncontaining .precipated magnesium hydroxide as the dispersing agent.

17. A latex-like disperson of an organic polysulphide derivativeproduced by the action of ethylene dihalide on a water solublepolysulphide of the formula RSn, wherein n is at least 3 and R is theequivalent of two monovalent positive radicals, said dispersioncontaining precipitated magnesium hydroxide as the dispersing agent.

18. A latex-like dispersion of an organic polysulphide derivativeproducedby the action of a mixture of dihalides of gaseous oleiins on awater soluble polysulphide of the formula RBn. wherein n is at least 3and R is the equivalent oftwo monovalentv positive radicals, saiddispersion con taining precipitated magnesium hydroxide as thedispersing agent.

. 19. A latex-like dispersion of an ethylene-polysulphide having asulphur content corresponding to a polysulphide of the formula RS,wherein n is at least 3 and R is the equivalent of two monovalentpositive radicals.

20. A latex-like dispersion of an organic poly- Mo use Patent No. 1,950,744.

JOSEPH c. PATRICK.

It is hereby certified that error appears in the printed-specificationof the above numhered'patent requiring correction as follows: -Page 1,line 66, for "'CaS47" read GaS4. 7; page 3, lines 69 and 70, for "in asolution of an aqueous polys'ulphide" read in an acqu'eoussolution of apolysulphide; and that the said Letters Patent should be read with thesecorrections therein that the same may conform'to the record of the casein the Patent Office.

Signed and sealed this 24th day of April, A. D. 1934.

Bryan M. I Batt ey (Seal) 7 Acting Commissioner of Patents.

March 13, 1934. Y

